package beartool;

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

public class Base64Encoder {
	private static char[] codec_table = { 'A', 'B', 'C', 'D', 'E', 'F', 'G',
		              'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T',
		              'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f', 'g',
		             'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't',
		             'u', 'v', 'w', 'x', 'y', 'z', '0', '1', '2', '3', '4', '5', '6',
		             '7', '8', '9', '+', '/' };
		 
		     public Base64Encoder() {		    	 
		     }
		 
		     public String encode(byte[] a) {
		         int totalBits = a.length * 8;
		         int nn = totalBits % 6;
		         int curPos = 0;// process bits
		         StringBuffer toReturn = new StringBuffer();
		         while (curPos < totalBits) {
		             int bytePos = curPos / 8;
		             switch (curPos % 8) {
		             case 0:
		                 toReturn.append(codec_table[(a[bytePos] & 0xfc) >> 2]);
		                 break;
		             case 2:
		 
		                 toReturn.append(codec_table[(a[bytePos] & 0x3f)]);
		                 break;
		             case 4:
		                 if (bytePos == a.length - 1) {
		                     toReturn
		                             .append(codec_table[((a[bytePos] & 0x0f) << 2) & 0x3f]);
		                 } else {
		                     int pos = (((a[bytePos] & 0x0f) << 2) | ((a[bytePos + 1] & 0xc0) >> 6)) & 0x3f;
		                     toReturn.append(codec_table[pos]);
		                 }
		                 break;
		             case 6:
		                 if (bytePos == a.length - 1) {
		                     toReturn
		                             .append(codec_table[((a[bytePos] & 0x03) << 4) & 0x3f]);
		                 } else {
		                     int pos = (((a[bytePos] & 0x03) << 4) | ((a[bytePos + 1] & 0xf0) >> 4)) & 0x3f;
		                     toReturn.append(codec_table[pos]);
		                 }
		                 break;
		             default:
		                 //never hanppen
		                 break;
		             }
		             curPos+=6;
		         }
		         if(nn==2)
		         {
		             toReturn.append("==");
		         }
		         else if(nn==4)
		         {
		             toReturn.append("=");
		         }
		         return toReturn.toString();
		 
		     }
		     public static String codeSha(String x){
		    	   MessageDigest md;
					try {
						md = MessageDigest.getInstance("SHA");
						md.update(x.getBytes());						
						return new Base64Encoder().encode(md.digest());
					}catch (NoSuchAlgorithmException e) {						
						e.printStackTrace();
					}
					return null;
		     }
		     public static void main(String[] args) {
		    	 System.out.println(Base64Encoder.codeSha("xiexh"));
					
			}
}
